The accusations, dating from 2013 through last year, were first announced by the group AIDS-Free World late on Wednesday.

Dujarric told reporters the UN can't confirm the allegations involving the dog at this point, but investigations continue.

"This issue has been out there in the public for almost a year [but] the allegations keep on coming," said Al Jazeera's James Bays, reporting from the United Nations in New York.

"People who were sent to protect the civilians are in fact becoming the perpetrators."

A report published in late January condemned the UN for failing to respond to allegations of child abuse against peacekeepers in the Central African Republic.

The independent investigation said the UN's handling of the case was "seriously flawed", accusing it of not taking the required action after the alleged abuse of young boys by French soldiers became known.

AIDS-Free World said 98 girls in CAR reported being sexually abused between 2013 and 2015 by perpetrators who have left the country.

It also said information on the alleged rape of a 16-year-old girl by a Congolese peacekeeper only three days ago in a hotel room has been turned over to the United Nations.

The UN has been in the spotlight for months over dozens of allegations of child rape and other sexual abuses by its peacekeepers, especially those based in CAR, which has faced sectarian violence since 2013.

Similar allegations have surfaced against the French force known as Sangaris, which operates independently in the country.

"We must face the fact that a number of troops sent to protect people instead acted with hearts of darkness," Dujarric said.

The UN human rights chief, Zeid Ra'ad al-Hussein, in a statement called the allegations "sickening".

He said all three countries whose peacekeepers are accused - Burundi, Gabon and France - have been formally notified.

Governments must do more to stop abuse and hold their troops accountable, "otherwise this awful cycle of abuse will never end", Hussein said.